Personal Research Database

Full Text: 1992\Wat Sci Tec25, 55.pdf

Abstract: The performance of Exxflow, a patented form of crossflow microfiltration, treating industrial wastewaters containing mixed heavy metals discharged by two types of industry is quantified and compared with the traditional technologies used for such treatment.

Pilot trial results using Exxflow are shown and compared to the performance of the full scale plants now operating on these effluents.

The operating costs of the Exxflow process are estimated for the two plants. One of which has been operating for 18 months and the other about 4 months.

The Exxflow process is described and improvements which are being developed to lower the operating costs are presented.

It is shown that industrial effluents containing mixed heavy metals are very effectively treated by the Exxflow process and since the installation of the plants the treated effluent has been of a quality suitable for discharge to the River Thames in one case and to a sewage treatment plant in the other.

Unlike other processes, Exxflow has shown that it can successfully treat effluent containing mixed metals and that removal of antimony from mixed metal waste waters is affected by the concentration of sodium sulphate in the wastewater.

Keywords: Mixed Heavy Metal Removal, Cross-Flow Microfiltration, Membrane Separation, Lead-Acid Battery Breaking Effluent, Antimony, Effluent Treatment

Literathy, P. (1992), Environmental consequences of the gulf war in Kuwait: Impact on water resources. Water Science and Technology, 26 (1-2), 21-30.

Full Text: 1992\Wat Sci Tec26, 21.pdf

Abstract: As a result of the iraqi occupation and the armed conflict in Kuwait 6 to 8 million barrels of crude oil were spilled into the marine environment, and about 2 to 3 million barrels of crude oil, burnt and unburnt, were being emitted daily during about 300 days into the environment from the burning or gushing oil wells. International efforts of UN agencies and other organizations from, the region and outside started immediately to assess the extent of the environmental pollution and to mitigate the adverse effects. In addition to the public health concerns of the air pollution caused by the burning wells, long-term environmental risk should be considered as a result of the oil spill into the marine and coastal environment, and the atmospheric fall-out, e.g., acid rain and petroleum related compounds associated with airborne particulates, in the marine and terrestrial areas. Particularly serious contamination of the desert ecosystem occurred around the damaged oilfields in Kuwait. The deposited crude oil and airborne particulates in the terrestrial areas may also affect the ground-water aquifer, Air quality, marine and desert soil pollution surveys provided data for a preliminary assessment and helped the formulation of mitigation and rehabilitation programmes, however, implementation of an integrated survey programme will ensure the final impact assessment on the environment, particularly on the marine and subsurface water resources.

? Tare, V., Chaudhari, S. and Jawed, M. (1992), Comparative evaluation of soluble and insoluble xanthate process for heavy metal removal from wastewaters. Water Science and Technology, 26 (1-2), 237-246.

Full Text: 1992\Wat Sci Tec26, 237.pdf

Abstract: Insoluble (ISX) and soluble starch xanthate (SSX) were synthesized in the laboratory from corn starch, and were used for metal [Cd(II), Cu(II) and Cr(VI)] removal from aqueous systems. Results indicate that soluble as well as insoluble xanthate processes are capable of meeting various effluent disposal standards. Metal removal by both the processes is maximum in the pH range 4 to 5. Mechanism of Cu(II)-xanthate and Cr(VI)-xanthate interaction is also discussed. From overall comparison of the two processes it appears that the insoluble xanthate process has an edge overthe soluble xanthate process in terms of metal removal capacity. reliability and ease of operation, particularly for cadmium removal. However, soluble xanthate process appears to be relatively less expensive compared to insoluble xanthate.

Keywords: Soluble Starch Xanthate, Insoluble Starch Xanthate, Heavy Metal-Xanthate Interaction, Cd(II), Cu(II), Cr(VI), Sorption, Precipitation, Starch Xanthate

? Meyer, V., Carlsson, F.H.H. and Oellermann, R.A. (1992), Decolourization of textile effluent using a low cost natural adsorbent material. Water Science and Technology, 26 (5-6), 1205-1211.

Full Text: 1992\Wat Sci Tec26, 1205.pdf

Abstract: To evaluate their abilities to remove colour from textile-plant effluents, tests were run using several low cost natural adsorbent materials including vermiculite, sawdust, barbecue charcoal, maize stalks, sand, rice husks and peatmoss. With the exception of vermiculite, more than 50% of the colour was removed from the wastewater, with barbecue charcoal and rice husks showing die best adsorptive qualities (67% and 65% respectively). Under simulated industrial conditions on a laboratory scale a fixed-bed reactor was used to investigate the adsorption capacity of barbecue charcoal with respect to colour removal. An average of 28% of colour was removed at a hydraulic retention time (HRT) of 1.6 h over a period of 25 days. The effect of pH on the adsorptive capacity with respect to colour removal and represents a relatively cheap adsorbent material compared to conventionally used granular activated carbon

Keywords: Activated Carbon, Adsorbent, Adsorption, Barbecue Charcoal, Basic-Dyes, Color Removal, Decolourization, Equilibrium, Fly-Ash, Hardwood, pH, Removal, Sawdust, Textile Effluent, Wastewater, Water

? Bailey, R.P., Bennett, T. and Benjamin, M.M. (1992), Sorption onto and recovery of Cr(VI) using iron-oxide-coated sand. Water Science and Technology, 26 (5-6), 1239-1244.

Full Text: 1992\Wat Sci Tec26, 1239.pdf

Abstract: A new adsorbent media has been prepared consisting of iron oxide coated onto sand surfaces. The oxide coating is made by adding a solution of a ferric salt and base to a mixture of sand and applying various heating protocols. The iron oxide is an excellent, regenerable adsorbent, and the process of coating it on sand allows the media to be used in a packed column. Depending on solution pH, the media can be made to adsorb either cationic or anionic metals. In this work, the media was used to collect hexavalent chromium from a synthetic waste stream. The influent contained 20 mg/L Cr(VI), and better than 99% removal was achieved consistently. Once breakthrough occurred, the media could be regenerated by exposure to base. The pH of the regenerant solution determined the kinetics and efficiency of the regeneration process. With further development, the process represents an inexpensive and effective method for removal and recovery of metals from industrial waste streams.

Keywords: Water, Chromium, Adsorption, Iron Oxides, Metal Recovery, Regeneration

? Dalmacija, B., Tamaš, Z. and Miškovic, D. (1992), The biosorption of selected pesticides from water by biologically activated carbon. Water Science and Technology, 26 (9-11), 1991-1994.

Full Text: 1992\Wat Sci Tec26, 1991.pdf

Abstract: The work describes a study of the possibility of removal of organo-phosphorus insecticide quinalphos and organochlorine herbicide lindane from water by using the biofilm formed on active carbon. It was established that two similtaneous processes took place in the biosorption column - adsorption and microbiological degradation of the adsorbed matter. At the shock concentrations of lindane in the influent, an inhibition of microbiological processes in the biofilm occurred. It was observed that the biosorption system was more efficient in the removal of the organo-phosphorus insecticide than of the organo-chlorine herbicide.

Keywords: Water, Biologically Activated Carbon, Lindane, Quinalphos, Removal

Susarla, S., Bhaskar, G.V. and Rao Bhamidimarri, S.M. (1992), Competitive adsorption of phenoxy herbicide chemicals in soil. Water Science and Technology, 26 (9-11), 2121-2124.

Full Text: 1992\Wat Sci Tec26, 2121.pdf

Abstract: A modified Freundlich-type bicomponent adsorption isotherm proposed by Sheindorf et al. (1981) was used to describe the competitive adsorption of 2,4-dichlorophenoxyacetic acid (2,4-d) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) onto volcanic soil. The adsorption capacities of 2,4-d and MCPA reduced in presence of the other component compared to pure component adsorption capacities.

Keywords: Equilibria

Pradhan, A.A. and Levine, A.D. (1992), Role of extracellular components in microbial biosorption of copper and lead. Water Science and Technology, 26 (9-11), 2153-2156.

Full Text: 1992\Wat Sci Tec26, 2153.pdf

Abstract: Binding of metal ions to extracellular components of microbial systems plays an important role in biosorption processes. Besides pH and temperature, type of anionic system and concentration of the metallic ions are some of the governing factors determining the maximum uptake capacity of the microbial system. Actinomycetes show an ability to selectively scavenge metals from aqueous systems. A biosorption system was tested using a bimetallic solution containing lead and copper. Uptake of Pb was observed to increase with concentration. Chloride ions had an inhibiting effect on the metal removal capacity of the actinomycetes system.

Keywords: Biosorption, Extracellular Binding, Metal Removal, Actinomycetes, Anionic Systems, Accumulation

D’Avila, J.S., Matos, C.M. and Cavalcanti, M.R. (1992), Heavy metals removal from wastewater by using activated peat. Water Science and Technology, 26 (9-11), 2309-2312.

Full Text: 1992\Wat Sci Tec26, 2309.pdf

Abstract: The processes used to remove heavy metals from inorganic wastewater have in general low efficiency. The use of activated peat obtained by using a process similar to a cation exchange reaction increases the removal efficiency up to five times when compared with peat ‘in natura’. The main objective of this work is to show the fundamental mathematical model, governed by diffusion process and the algorithms utilized to design the batch and the continuous feed stirred tank reactors or in some cases a fixed bed reactor. The principal dimensions of these equipments are obtained from the knowledge of the activated peat’s cation exchange capacity used in the process, and the main chemical characteristics of the heavy metal ion contained in the wastewater. Besides, two important parameters are also included: the ion concentration and the efficiency of the process obtained from laboratory kinetics experiments. For example Pb²⁺ is removed from a wastewater at a concentration of 50g/m³ in five minutes or less, with an efficiency of 98%.

Keywords: Waste-Water Treatment, Activated Peat, Heavy Metals, Pollution Control, Inorganic Waste

? Lee, J., Chen, B., Allen, H.E., Huang, C.P., Sparks, D.L. and Sanders, P. (1992), Trace metal soil quality criteria to protect groundwater. Water Science and Technology, 26 (9-11), 2327-2329.

Full Text: 1992\Wat Sci Tec26, 2327.pdf

Abstract: A major problem in site remediation is frequently the lack of appropriate standards for pollutants in soil. Lack of standards for an exposure route can result in subjective judgments regarding the extent of remediation needed. These problems are particularly important when considering the potential for groundwater contamination by inorganic materials. The partitioning of trace metals is highly dependent on the nature of the soil and on the solution pH. The maximum level of metal in soil for which the equilibrium soluble metal does not exceed the drinking water standard can be computed, at any pH, from the measured partition coefficient for any metal and soil.

The sorption of cadmium and lead onto major types of New Jersey soil has been determined as a function of pH. As the pH decreased, the amount of adsorbed metal decreased.

As is conventionally done, we have transformed these data into sorption coefficients (K(d)) which are a function of pH. To apply such data in the decision making process, it is necessary to use the K(d) and appropriate conditions of soil/groundwater in the environment. The calculation determines the maximum concentration of metal which will not result in exceedence of water quality standards. These criteria can be used as a soil standard which will be protective of groundwater quality.

We developed adsorption/desorption relationships in the form of a mathematical model and computed the maximum level of metal in soil for which the equilibrium soluble metal will not exceed the drinking water standards.

Schrale, G., Boardman, R. and Blaskett, M.J. (1993), Investigating land based disposal of bolivar reclaimed water, South Australia. Water Science and Technology, 27 (1), 87-96.

Full Text: 1993\Wat Sci Tec27, 87.pdf

Abstract: The Bolivar Sewage Treatment Works (STW) processes the urban and industrial sewage from the northern and eastern suburbs of Adelaide. The treatment capacity is equivalent to the sewage production of 1.1 million people. The disposal of more than 40000 ML of reclaimed water into the sea has caused a progressive degradation of about 950 ha of seagrass beds which threatens the sustainability of the fisheries and marine ecosystems of Gulf St. Vincent. The current practice will no longer be viable to achieve compliance with the SA Marine Environment Protection Act, 1990. A Inter-Departmental Working Party recommended that the Bolivar reclaimed water be disposed by irrigation of suitable land on the coastal plains north of Adelaide. They proposed the construction of two pipelines: a 12 km long pipeline to extend the distribution of reclaimed water in the most intense portion of the 3500 hectares of irrigated horticulture on the Northern Adelaide Plains, and a second, 18 km long pipeline to deliver the remainder to a more northerly site for irrigation of an estimated 4000 hectares of hardwood plantations. The paper summarizes the findings as they relate to public health, environmental, technical and financial aspects of land based disposal. Land based disposal would completely eliminate the marine degradation and also arrest the over-use of the NAP underground water resources for horticulture. The total net costs over thirty years for land bared disposal are about $ 21.8 million. The ‘horticultural’ pipeline of the land based disposal scheme is expected to be commercially viable. A shortfall in revenue from the afforestation component is expected and may need to be considered as an environmental cost of ceasing marine disposal.

? Mann, R.A. and Bavor, H.J. (1993), Phosphorus removal in constructed wetlands using gravel and industrial waste substrata. Water Science and Technology, 27 (1), 107-113.

Full Text: 1993\Wat Sci Tec27, 107.pdf

Abstract: The phosphorus removal efficiency of three gravel based constructed wetland systems (CWSs) has been investigated in a two year study in which secondary sewage effluent was treated. The constructed wetlands systems, 100m x 4m x 0.5m with an impervious liner, comprise an unplanted gravel “control” trench and gravel trenches planted with monoculture stands of either Typha orientalis or Schoenoplectus validus. Inlet and outlet phosphorus concentrations and vertical and linear profiles of phosphorus were determined to characterise immobilisation / translocation through the systems. Laboratory phosphorus adsorption experiments were conducted with regional gravels and alternative adsorptive media including industrial slag and ash by-products. Phosphorus adsorption in the large scale gravel systems was variable and ranged from -40% to 40%. Laboratory adsorption capacity studies conducted with the gravel substratum indicated that field adsorption potential could be successfully simulated and modeled. Ion exchange experiments have been used to evaluate gravel and industrial conglomerates, with a view to improving phosphorus immobilisation through substratum selection and effluent flow management. Langmuir and Freundlich isotherms characterised phosphorus adsorption and the maximum adsorption capacity of regional gravels ranged from 25.8 to 47.5 mug P/g compared to blast furnace slag 160 to 420 mug P/g and fly ash 260 mug P/g. These results indicate that further investigations into the inclusion of industrial waste substrata in a CWS are warranted.

Keywords: Phosphorus Removal, Constructed Wetlands, Gravel Adsorption, Industrial Wastes, Ion Exchange, Langmuir Isotherm, Freundlich Isotherm, Phosphate Adsorption, Water, Soils, Slag

Edzwald, J.K. (1993), Coagulation in drinking water treatment: Particles, organics and coagulants. Water Science and Technology, 27 (11), 21-35.

Full Text: 1993\Wat Sci Tec27, 21.pdf

Abstract: A review of coagulation in drinking water treatment is presented. The paper emphasizes the importance of raw water chemistry, natural organic matter (NOM) concentration and type, and the chemistry of coagulants. Mineral and organic particles may be stable in water due to electrostatic charge interactions, hydrophilic effects, or to steric interactions from adsorbed macromolecules. NOM rather than particles initially in water supplies can control coagulant dosages and selection. NOM consists of a mixture of various organic compounds including hydrophobic (humic and fulvic acids) and hydrophilic fractions. The negative charge and chemical structure of the hydrophobic acids affect chemical reactions with coagulants, particularly metal based coagulants. The removal of NOM with Al coagulants can involve hydrolysis, complexation, precipitation, and adsorption reactions. Specific ultraviolet absorbance (SUVA) can be used to estimate whether the NOM of a water is high or low in hydrophobic acids and to estimate removals of DOC by coagulation. Preozonation of water supplies containing algae may lead to microflocculation or impair coagulation depending on algae type, concentration and molecular weight of extracellular organic matter (EOM), and ozone dose.

Keywords: Coagulation, Drinking Water, Aluminum Coagulants, Natural Organic Matter, Particle Stability, Algae, Ozone, Polyaluminum Chloride, Chemical Aspects, Aluminum Salts, Matter, Destabilization

Orhan, Y. and Büyükgüngör, H. (1993), The removal of heavy metals by using agricultural wastes. Water Science and Technology, 28 (2), 247-255.

Full Text: W\Wat Sci Tec28, 247.pdf

Abstract: The removal of heavy metals from wastewater using adsorbants such as waste tea, Turkish coffee, exhausted coffee, nut and walnut shells has investigated. Batch studies were conducted at room temperature and adsorption experiments were carried out by shaking 0.3 g of adsorbent with 100 ml synthetic wastewater containing Cr(VI), Cd(II) and Al(III) metal ions. The remaining concentration of heavy metals in each samples after adsorption at various time intervals was determined spectrophotometrically. Batch studies showed that these adsorbents exhibit a good adsorption potential for Al(III) metalions. The adsorption ratios of Al(III) were as 98, 99, 96, 99.5 and 96% for waste tea, Turkish coffee, exhausted coffee, nut and walnut shells, respectively. These results were compared with those obtained using activated carbon as adsorbent. The batch adsorption kinetics and adsorption equilibria were examined and described by a first order reversible reaction and Freundlich isotherm, respectively. The first order rate and isotherm constants have been calculated.

Keywords: Adsorption, Agricultural Wastes, Metal Ions, Equilibrium Isotherms

Lo, K.S.L. and Leckie, J.O. (1993), Kinetic studies of adsorption-desorption of Cd and Zn onto Al₂O₃/solution interfaces. Water Science and Technology, 28 (7), 39-45.

Full Text: 1993\Wat Sci Tec28, 39.pdf

Abstract: The effects of external and internal mass transport limitations on zinc and cadmium adsorption onto the porous amorphous aluminium oxide/solution interfaces were studied. A modified two-stage rate model was used to interpret the experimental results. The rapid stage results from external surface film diffusion and internal diffusion into the near surface pores. The slow stage results from internal mass transport and extends over several days. The mass transfer-adsorption coefficients of the rapid stage are almost two orders of magnitude larger than those of the slow stage. The external mass transfer coefficients show an increasing trend with increasing pH, and appear to be affected by the charge/potential condition of the oxide/solution interface. The internal mass transfer coefficients indicate a uniform trend for both the zinc and cadmium results. The desorption rates and final metal ion solution concentrations are affected by the bulk solution pH. Film diffusion and internal diffusion are affected by the higher relative ratio of metal ion concentration to adsorbent concentration.

Keywords: Heavy Metal, Adsorption, Metal Oxide, Amorphous Aluminum Oxide, Internal Mass Transport

Mino, T. (1993), Comparison of legislation for water pollution control in Asian countries. Water Science and Technology, 28 (7), 251-255.

Full Text: 1993\Wat Sci Tec28, 251.pdf

Abstract: Information on legislative and administrative water pollution control systems in ten Asian countries was collected through direct contact or mail correspondence with relevant government officials or engineers. Effluent concentration control is the most common system to control water pollution. Effluent standard values in the countries examined are compiled and the structural differences of the effluent control systems are discussed. Japan has relatively lenient standards, but because of its supporting measures for the implementation of the effluent standard system it has achieved satisfactory water pollution control.

Keywords: Water Pollution Control, Effluent Concentration Control, Effluent Standards, Asian Countries

Tam, N.F.Y. and Wong, Y.S. (1994), Nutrient and heavy metal retention in mangrove sediment receiving wastewater. Water Science and Technology, 29 (4), 193-200.

Full Text: 1994\Wat Sci Tec29, 193.pdf

Abstract: Soil column studies were carried out to examine the capacity of mangrove sediments in retaining wastewater nutrients and heavy metals. Synthetic wastewater of three different concentrations, namely diluted sewage (DW), medium sewage (MW) and concentrated sewage (CW), were applied to the columns daily over a period of 54 days. Leachate from each column was collected and analyzed. The study revealed that the concentrations of ammonium in the leachates from all sewage treatments decreased dramatically in the first week with a pattern similar to the control. After this initial decrease, ammonium contents increased rapidly especially in the column treated with CW, then remained at a steady level. At the end of the experimental period, the concentrations of ammonium found in the leachate were in the declining order of CW > MW > DW > control. Organic nitrogen, nitrites and nitrates were not detected in the leachates from all sewage treatments. This suggested that denitrification might have occurred and some of the nitrogen from sewage might have been retained in the mangrove sediment. The changes in leachate K concentration were similar to that of NH₄⁺-N content. On the other band, the soluble phosphorus and heavy metal contents of leachates from sewage treated columns were similar to those of the control. Most of the heavy metals, including Cu, Zn and Cd, were not detected in the leachate. The sediment data showed that NH₄⁺-N, ortho-P, and heavy metals were accumulated on the top layer of the soil column and their contents decreased with the depth of the soil column. The highest metal content was found in the column treated with concentrated sewage. It is clear that mangrove sediments acted as a good filter/trap for phosphorus and metals, but were less efficient for ammonium nitrogen.

Keywords: Mangrove Sediment, Wetland, Waste-Water Treatment, Nutrients and Heavy Metal Retention, Sphagnum Peat, Water

? Suschka, J., Morel, J., Mierzwinski, S. and Januszek, R. (1994), Full scale treatment of phenolic coke coking waste water under unsteady conditions. Water Science and Technology,